According to the Nuremberg code 1947: The voluntary consent of human subjects is essential, subjects must have legal capacity and freedom of choice to consent without coercion. Subjects must understand what they are consenting to. Placebo trials are permissible because they can yield socially beneficial results and find new effective treatments that are better than existing options, as receiving placebos does not mean receiving no treatment. Placebo-controlled trials are needed in some medical areas to reliably demonstrate treatment efficacy.